Electric switch and contact structure therefor



Jim 1933. s. w. OKEEFFE 1,395,757

ELECTRIC SWITCH AND CONTACT STRUCTURE THEREFOR Original Filed Jan. 24, 1929 3 Sheets-Sheet 1 Jan. 31, 1933. G w OVKEEFFE 1,895,767

ELECTRIC SWITCH AND CONTACT STRUCTURE THEREFOR Original Filed Jan. 24, 1929 5 Sheets-Sheet 2 3 Sheets-Sheet 3 G. W. OKEEFFE Original Filed Jan. 24, 1929 ELECTRIC SWITCH AND CONTACT STRUCTURE THEREFOR QMQQW Jan. 31, 1933.

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Patented Jan. 31, 1933 UNITED STATl -IS PATENT OFFICE GEO BGE W. OKEEFFE, OI KIIiTON, KABSACHUSETTS, ASSIGNOR TO CONDIT ELECTRICAL MANUFACTURING OOBPOBATION,,OF SOUTH BOSTON, IABSACHUSETTS, A CORPO- BATION OF MASSACHUSETTS ELECTRIC SWITCH AND CONTACT STRUCTURE THEREFOR Original application filed January 24,

This invention relates to electric switches especially adapted, although not necessarily limited, to the control of industrial motor circuits.

An object of the present invention is an electric switch and a contact member therefor which provides two contact sections adapted separately to cooperate with separate cooperating contact members for the purpose of bridging them.

A further object of the invention is the provision of a contact member and a supporting structure therefor on which the contact member is held removably in operative position, the supporting structure being so arranged that the contact member canbe removed from operative position without removing any attaching parts.

A further object of the invention is generally to improve the construction and operation of electric switches and contact structures therefor.-

This application is a division of my copending application Serial No. 334,783, filed January 24, 1929.

Fig. 1 is a front elevation of an electric switch embodyin the present invention, the enclosing casing ing broken awa Fig. 2 is a sectional elevation ta en along line 2-2 of Fig. 1. Fig. 3 is a section taken along line 3-3.of Fig. 2.

Fig. 4 is a section taken along line 44 of Fig. 3.

Fig. 5 is a perspective view of the movable contact member.

Fig. 6 is a perspective view of the holding frame for the contact member.

The switch here shown as embodying the invention is contained within an enclosing casing having the fixed part 10 and. the cooperating removable part 12 which constitutes a cover for the fixed part. The switch includes a switch frame having spaced vertical side plates 14 which are connected in spaced relation at their lower ends by the core 16 of the electro-magnet for the operating mechanism, which core is located between and is riveted to said side plates. An insulating contact carrying frame 18 compris- 1928, Serial No. 884,783. Divided and this application filed February 20, 1929. Serial No. 341,519.

ing a rectangular plate of molded insulating material is secured in horizontal position removably to the upper ends of said side plates. A plurality of sets of contact members are carried by said plate, each set comprising three spaced and insulated contact membersv 20, 22 and 24, which are arranged in line has struck-out spheroidally shaped bosses 32 which project from one face thereof at the ends of thebar. The inner boss of an outer contact member and the adjacent boss of the intermediate contact member 22 are adapted to be engaged by a movable contact member whereby to connect them electrically. The switch herein described is arranged to provide four serially connected points of circuit interruption in each phase conductor of the circuit.

The movable switch member includes a rectangular insulating contact-supporting plate 34 which is located beneath the stationary insulating plate 18. Said plate is carried removably in a movable supporting frame 36 and is slidable on inwardly extended tracks for said parallel arms 38 thereof which constitute supporting tracks for said insulating plate 34. Said plate can be withdrawn from said tracks by movement horizontally thereof whereby to remove the plate. and the contact carried thereby entirely from the switch. Said supporting frame 36 is guided for vertical movement in parallel lines to and from switch closed position by sliding engagement with tracks 40 of the side plates 14 of the frame.

Two operating mechanisms, indicated generally at 42, are carried by said side plates and have link connections with the opposite sides of said supporting frame whereby to Each contact member, as the contact member 20, consists of a relatively thick elongated bar which or winding 47 of said magnet is energized, the supporting frame and the movable contact carrying plate are caused to be raised 1 to move the contact member carried by said lower plate into engagement with the stationary contact members carried by the upper plate. The electro-magnet is adapted to remain'energized for so long as the switch is adapted to remain closed and when the electro-magnet is dc-energized the switch is adapted to open.

The lower insulating supporting plate 34 has sets of movable contact members thereon corresponding to the number of sets of stationary contact members. Each set of movable contact members comprises two contact members 48 which are arranged in spaced relation on the upper face of said insulating plate 34 and each is adapted independently to connect a separate outer stationary contact member with the common intermediate contact member.

The movable contact members 48 are essentially identical in construction with the stationary contact members. -Each movable contact member comprises a relatively thick elongated bar which has struck-out spheroidally shaped bosses 50 which extend above the upper face of the bar at the ends 'thereof.

Recesses 52 complemental with the bosses-50 are present in the lower faces of said contact member. A. vertically elongated recess 54 is located in the middle of the contact member between the recesses 52. Means are provided to support said contact member yieldingly above the upper face of the insulating carrying plate 34 and said means are also so constructed as to permit the removal of said contact member from operative position on said plate without the necessit for detaching any attaching parts.

'ihe supporting means for the contact member includes a frame or contact holder 56 of more or less channel shape, see especial- .ly Fig. 7, which has the horizontal bottom member 58 and the integrally-connected spaced upstanding arms 60, the upper ends of which are reflexed inwardly in opposed parallel relation with each other and constitute abutments 62 which overlie the upper face of said contact member between the bosses 50 and limit the elevated position of said contact member. Said insulating-suporting plate 34 is provided with a rectanguar recess 64 in which the lower portion of said frame is received, the bottom member 58 of said frame being seated upon the fiat bottom of said recess. The contact member is supported on a vertical pin 66 which has a reduced and rounded upper end 68 which is received loosel in the recess 54 of the contact member. T e pin also has an enlarged section or flange 70 below said reduced upper end u on which the contact member is seated. aid reduced end 68 and flange 70 constitute a universal or rocking seat on which the contact member can rock to align itself in contact with an outer and an intermediate stationary contact member. A helical compression spring 72 encircles said pin. 66 and bears at its upper end against the flange 7 O and at its lower end upon the bottom member 58 of the frame 56 whereby to press the contact member yieldingly against the under face of the abutments 62 of said frame, thereby holding the contact member yieldingly in elevated and operative position, when the switch is open. When the switch is closed, the movable contact member is depressed below said abutments and is maintained against said cooperating stationary contact members, by the pressure of said spring. Said pin 66 is loosely extended through an opening in the bottom member of said supporting frame and also through an opening in the insulatedsupporting plate 34. The lower extended end of said pin is provided with a reduced end 74 on which a button 76 is secured. Said button is adapted to be grasped by the flanges to pull the pin 66 downwardlyand compress the sprmg 72. When the pin is inthis position, the contact member can be detached from the reduced end 68 of the pin and withdrawn from the supporting frame 56.

When the contact'member is withdrawn, and the pin 66 is released the spring 72 is adapted to hold the button 76 against the underside of the insulating plate 34 and also to hold the frame 56 against said plate wherebyto prevent the frame from becoming detached from the plate when the contact member is removed.

engage said'flat surface between said contact faces, and means yieldingly holding said contact member in the aforesaid relation including a pin which is received loosely with in said contact member under said abutment. member, and a spring urging said pin against said contact member.

2. In an electric switch, an elongated contact member having contact faces at its opposite ends and a recess between'said contact faces, a supporting pin having its end received within said recess and having an en- 130 I said pin in a direction to maintain said con tact member yieldingly against said abutment, and means to depress said pin against the action of said spring to remove it from said recess and permit the removal of said contact member from beneath said abutment free from said supporting pin 3. In an electric switch, a contact carrier having opposed abutments, a contact member located loosely within said carrier having end contact faces and an intermediate supporting position which rests a ainst said abutments, a supporting pin loose y received in said contact member on the side of said supporting portion remote from and within said contact member yieldingly against said abutments, said pin being removable from his said contact member against the action of said spring wherebyt to release said contact member and permit it to be detached from said support and removed from said carrier.

4. In an electric switch, an insulating sup- .porting plate, a contact enclosing frame having an abutment member resting on said plate and spaced upstanding arms provided with inturned projections at the upper ends of said arms, a contact member located within said arms andin normal enga ement with said projections, a pin loose y extended through said abutment member and through said plate and having a button thereon beneath said plate, said pin having its upper end located loosely in said contact member and having an enlargement therebeneath on which said contact member is supported, and a spring encircling said pin and bearing upon said bottom member and against said pin and holding said contactmember yieldably in elevated position against said projections.

5. In an electric switch, an insulating supporting plate, a contact enclosing frame having an abutment member resting on said plate, and spaced upstanding arms provided with inturned projections at the upper ends of said arms, a contact member located within said arms and in normal engagement with said projections, a pin looselyextended through said abutment member and through said plate and havin a button thereon beneath said plate, sai pin having its upper end located loosely in said contact member and having an enlargement therebeneath on which said contact member is supported, and

a spring encircling said pin and bearing upon said bottom member and against said pin and holding said contact member yieldably in elevated position against said projections, said spring also constituting the means to hold said. abutment member against said insulating plate.-

6. In an electric switch, an insulating plate having'a rectangular recess therein, a contact supporting frame having a bottom member seated upon the bottom of said recess and spaced upstanding arms engaging the sides of said recess and extended above said plate and the upper ends provided with inturned opposed ends constituting abutments, a con-- tact member located within said arms and having its upper face bearing against said abutments, a pin passed loosely through said plate and bottom member having a button at the lower end disposedbeneath said insulating plate, said pin having its upper end received loosely within said contact member and having an enlargement thereunder on which said contact member is seated, and a spring encircling said vpin and bearingagainst said enlargement and said bottom member and constituting means to hold said contact member yieldably in elevated position, said pin arranged to be withdrawn from engagement with said contact member where: by to permit said contact member to be removed from said frame.

7. In an electric switch, a contact support comprising an insulating plate, a frame carried by the upper surface of said plate havi ing upper and lower spaced abutments, a plunger extended through said insulating plate and the lower abutment of said frame and terminated beneath the upper abutment thereof in an enlarged end portion, a retractile spring encircling said plunger and bearing at its opposite ends against saidenlarged end portion and the lower abutment of said frame whereby to urge said plunger upwardly in the direction of said upper abut-Y merit, a contact member adapted to be received within said frame comprising an elongated bar having contact portions at its ends and an intermediate attaching portion which is received beneath the upper abutment of said frame, said attaching portion having a recess in its lower face in which the upper end of said plunger is loosely received, said plunger under the action of sai spring constituting the sole attaching means for said contact member, and means carried by the lower end of said plunger beneath said in sulating plate for depressing said plunger to liberate said contact member and permit it to be withdrawn from beneath said upper abutment free from said frame and plunger.

8 In an electric switch an insulating contact support, a frame carried b ments, a plunger extended through the lower said support having spaced upper and ower abutabutment of said frame and terminated beneath the upper abutment in an enlarged end portion, a retractile spring encircling said plunger and bearing at its opposite" ends against the enlarged end portion of said pin and the lower abutment of said frame, and a contact member comprising an elongated bar having contact portions at'its ends and having an intermediate portion 'therebetween which is received beneath. said upper abutment of said frame, said attaching portion having a recess in its lower face in which the upper end of said plunger is loosely received, said plunger hav ng provision for depressing it whereby to liberate said pin from the recess of said contact member and permit said contact member to be withdrawn from said frame while maintaining said plunger, and frame in position on said insulating support.

9. In an electric switch, the combination of a contact member comprising an elongaied bar having contact faces at its opposite ends and a flat face in the middle thereof between the contact faces, and a holder which releasably retains said bar and in which the bar is vertically movable and also tiltable, said holder comprising a frame having upstand ing spaced arms which overlie the opposite edges of the bar and restrain it against lateral displacement, the bar being vertically movable between said arms, said arms having inturned ends which overlieand engage the flat face of the bar and limit the vertical movement thereof in one direction, and spring means located within the space between said arms and bearing against the bar under the fiat face thereof and maintaining said flat face resiliently against the inturned ends of said arms. I

10. In an electric switch,-the combination of a contact member comprising an elongated bar havingcontact faces at its opposite ends and a flat face in the middle thereof beiween the contact faces, and a holder whith releasably retains said bar and in which the bar is vertically movable and also-tiltable, said holder comprising a frame having upstanding spaced arms which overlie the opposite edges of the bar and restrain it against lateral displacement, the bar being vertically movable between said arms, said arms having inturned ends which overlie and engage the fiat faces of the bar and limit the vertical movement thereof in one direction, said hofder arms having a connecting member between them at the end opposite said inturned ends, and spring means located in the space between saidarms and bearing against said connecting member and also against said bar under the flat face thereof and maintaining said flat face releasably in engagement with the inturned ends ofsaid arms.

11. In an electric switch, the combination of a contact'member comprising an elongated bar having contact faces at its opposite ends and a fiat face in the middle thereof between the contact faces, and a holder which releasably retains said bar and in which i the bar is vertically movable and also (iltable, said holder comprising a frame having upstanding spaced arms which overlie the opposite edges of the bar and restrain it against lateral displacement, the bar being vertically movable. between said arms, said arms having inturned ends which overlie and engage the flat face of the bar and limit the vertical movement thereof in one direction, said holder arms having a connecting member between them at the end opposite said inturned ends, and spring means located in the space between said arms and bearing against said connecting member and also against said bar under the flat face thereof and maintaining said fiat face releasably in engagement with the inturned ends of said arms, said spring means having a releasable connection withsaid bar so that said bar can be removed from said holder independently of said spring means. 1

12. In-an electric switch, the combination of a contact member comprising an elongated bar having contact faces at its opposite ends able between said arms, said arms having inturned ends which overlie and engage the fiat face of the bar and limit the vertical movement thereof in one direction, a pin In testimony whereof, I have signed my nameto this application.

GEORGE W. OKEEFFE. 

